The age-adjusted hazard for MI declined by 62% among British men who were followed for 25 years.
Cardiovascular disease is the leading cause of death in the U.K., but the incidence of myocardial infarction has fallen in recent years. British Regional Heart Study investigators have examined whether this decline reflects changes in cardiovascular risk factors.Among 7735 men who were followed for 25 years, the age-adjusted hazard for MI decreased by 3.8% annually, which corresponded to a 62% decline during the 25-year period. Beneficial trends were decreases in cigarette smoking, systolic blood pressure, and non–HDL cholesterol levels, and increases in HDL cholesterol and physical activity levels. A potentially harmful trend was increased body-mass index. No significant changes in alcohol consumption were noted, and diabetes was not assessed. Declines in cigarette smoking accounted for 23% of the reduction in MI incidence; improvement in blood pressure accounted for 13%; changes in HDL cholesterol levels for 12%; and reductions in non–HDL cholesterol levels for 10%. Physical activity and alcohol consumption had no significant effects.Comment: In this analysis, changes in four traditional risk factors (cigarette smoking, blood pressure, HDL cholesterol levels, and non–HDL cholesterol levels) accounted for approximately half the reduction in MI incidence over time. The analysis did not distinguish between improvements that resulted from lifestyle changes and those that were related to medication. The good news is that even modest changes in risk factors can substantially lower risk for MI, but rising BMI (and presumably, more diabetes) might counteract these otherwise favorable findings.
— Kirsten E. Fleischmann, MD, MPH
Published in Journal Watch General Medicine March 11, 2008
Citation(s):
Hardoon SL et al. How much of the recent decline in the incidence of myocardial infarction in British men can be explained by changes in cardiovascular risk factors? Evidence from a prospective population-based study. Circulation 2008 Feb 5; 117:598.